Identify a pattern in the list of numbers. Then use this pattern to find the next number.

3, -15,75,- 375,1875, ​___

The pattern in the list of numbers is that each number is obtained by multiplying the previous number by -5.

Using this pattern, the next number would be obtained by multiplying 1875 by -5:

Next number = 1875 * -5 = -9375

Therefore, the next number in the pattern is -9375.

To identify the pattern in the list of numbers, let's take a look at the differences between consecutive terms:

- The difference between the first and second terms is (-15 - 3) = -18.
- The difference between the second and third terms is (75 - (-15)) = 90.
- The difference between the third and fourth terms is (-375 - 75) = -450.
- The difference between the fourth and fifth terms is (1875 - (-375)) = 2250.

From this, we can observe that the differences alternate between negative and positive, and increase in magnitude with each term. The pattern seems to be that each term is obtained by multiplying the previous term by -5.

Using this pattern, we can find the next term by multiplying the last term (1875) by -5:
Next term = 1875 * -5 = -9375.

Therefore, the next number in the pattern is -9375.